The invention relates to a centrifuge for the continuous separation of substances that differ in density, particularly for separating solid-liquid mixtures. More particularly, the centrifuge comprises an essentially cylindrically shaped drum with nozzles arranged in the discharge region for the thick substances. The discharge region openings through which the thick substance is discharged, and control elements that cooperate with an adjustment means arranged outside of the centrifuge drum are provided for opening and closing the nozzle openings.
German Published Application 36 20 912 discloses a centrifuge for the continuous separation of substances that differ in density which conforms to the above type, with control elements that accomplish the opening and closing of the nozzles arranged inside the centrifuge drum. Piston-cylinder units are also provided as adjustment agents to which bores, that are arranged in the end wall and in the drive shaft of the centrifuge drum, are connected. These bores lead to the outside and serve as hydraulic fluid lines that are charged with hydraulic fluid from the outside. This known mechanism for opening and closing the nozzles is not only relatively complicated in terms of structure, but repair thereof, particularly the replacement of worn control elements for new control elements, involves a relatively great expenditure of work, time and money since the centrifuge not only has to be stopped for this purpose, but for thick material, the centrifuge drum must also be opened in the region of the discharge. Moreover, the delivery of the hydraulic fluid to the control elements arranged inside the centrifuge drum is accompanied by sealing problems that are extremely difficult to govern, particularly in the region of the rotary transmission leadthrough.
An object of the invention is to considerably simplify the discharge of thick material from the centrifuge independently of the speed of the conveyor worm and/or of the differential speed between conveyor worm and centrifuge drum.
A further object of the invention is to provide an improved rotary centrifuge separating a mixture of solids and liquids which avoids the disadvantages existent in structures and arrangements of the type heretofore available to the art.